I have my swatches in a window with only a few hours of sun a day. This is early spring, so weak sunshine. Because of that, I am shocked at these results:
Beige is gone, peach is beige, carmine and ultramarine are phantoms. Phthalo is faded, the yellows, I don’t know about the brown, maybe faded a little. Yellow and brown are supposed to have excellent lightfastness, according to the ratings: https://www.dickblick.com/products/blick-studio-artists-colored-pencils/ -> Item Specs.
Actually, my shock at the Progresso colors is how well they did relative to Dick Blick Studio. They have similar fading, but Progressos have no lightfastness ratings. And they’re cheaper.
I didn’t expect any change at all in the polychromos. But I see a little. I wonder if the paper has an effect? It’s supposed to be acid-free, but it darkened. It’s Bienfang mixed media paper. It’s student grade.
I have my pigments phthalo blue Pb15:3, hansa yellow Py74 and quinacridone magenta Pr122 mixed into egg yolk and painted onto the same paper. When they’ve been in the window for 2 months, I’ll post and compare.
Update 9th of May, 2020: here’s the pigments:
They’re all exactly the same. I know the pic makes the yellows seem different, but to my eye, they are still exactly the same yellow in real life. The paper made no difference with these egg tempera colors.
cindy moon mckee 